diff --git a/README.md b/README.md
index d32c00d..d9018b4 100644
--- a/README.md
+++ b/README.md
@@ -123,8 +123,8 @@ result = event_store.append(
 case result
 in En57::Success(position:)
   # credits consumed at event position
-in En57::Failure
-  # lost the race; another writer already consumed credits
+in En57::Failure(position:)
+  # lost the race; another writer already consumed credits at position
 end
 ```
 
@@ -161,7 +161,7 @@ result = event_store.append(
 case result
 in En57::Success(position:)
   # user registered at event position
-in En57::Failure
-  # email already used
+in En57::Failure(position:)
+  # email already used at event position
 end
 ```
diff --git a/db/schema/0.1.0.sql b/db/schema/0.1.0.sql
index 67c05f1..4976580 100644
--- a/db/schema/0.1.0.sql
+++ b/db/schema/0.1.0.sql
@@ -45,6 +45,7 @@ DECLARE
     req_tags text[];
     req_after bigint;
     appended_position bigint;
+    matched_position bigint;
 BEGIN
     FOREACH criterion IN ARRAY criteria LOOP
         req_after := (criterion ->> 'after')::bigint;
@@ -54,43 +55,43 @@ BEGIN
         req_tags := ARRAY ( SELECT DISTINCT
                 jsonb_array_elements_text(COALESCE(criterion -> 'tags', '[]'::jsonb)));
         IF cardinality(req_tags) > 0 THEN
-            IF EXISTS (
+            SELECT
+                max(e.position)
+            FROM (
                 SELECT
-                    1
-                FROM (
-                    SELECT
-                        t.event_id
-                    FROM
-                        en57.tags AS t
-                    WHERE
-                        t.value = ANY (req_tags)
-                    GROUP BY
-                        t.event_id
-                    HAVING
-                        count(*) = cardinality(req_tags)) AS matched
-                    JOIN en57.events AS e ON e.id = matched.event_id
-                WHERE (req_after IS NULL
-                    OR e.position > req_after)
+                    t.event_id
+                FROM
+                    en57.tags AS t
+                WHERE
+                    t.value = ANY (req_tags)
+                GROUP BY
+                    t.event_id
+                HAVING
+                    count(*) = cardinality(req_tags)) AS matched
+            JOIN en57.events AS e ON e.id = matched.event_id
+        WHERE (req_after IS NULL
+                OR e.position > req_after)
                 AND (criterion -> 'types' IS NULL
-                    OR e.type = ANY (req_types))) THEN
-        RETURN ROW ('append_condition_violated',
-            NULL)::en57.append_result;
-        END IF;
-    ELSE
-        IF EXISTS (
+                    OR e.type = ANY (req_types))
+            INTO
+                matched_position;
+        ELSE
             SELECT
-                1
+                max(e.position)
             FROM
                 en57.events AS e
             WHERE (req_after IS NULL
                 OR e.position > req_after)
-            AND (criterion -> 'types' IS NULL
-                OR e.type = ANY (req_types))) THEN
-    RETURN ROW ('append_condition_violated',
-        NULL)::en57.append_result;
-    END IF;
-END IF;
-END LOOP;
+                AND (criterion -> 'types' IS NULL
+                    OR e.type = ANY (req_types))
+            INTO
+                matched_position;
+        END IF;
+        IF matched_position IS NOT NULL THEN
+            RETURN ROW ('append_condition_violated',
+                matched_position)::en57.append_result;
+        END IF;
+    END LOOP;
     WITH inserted_events AS (
 INSERT INTO en57.events (id, type, data, meta)
         SELECT
diff --git a/lib/en57.rb b/lib/en57.rb
index 171dcc0..6f8a7bb 100644
--- a/lib/en57.rb
+++ b/lib/en57.rb
@@ -15,7 +15,7 @@ require_relative "en57/configuration"
 
 module En57
   Success = Data.define(:position)
-  Failure = Data.define
+  Failure = Data.define(:position)
   AppendRetriesExhausted = Class.new(StandardError)
 
   def self.configuration = Configuration.instance
diff --git a/lib/en57/repository.rb b/lib/en57/repository.rb
index 2297259..323da9a 100644
--- a/lib/en57/repository.rb
+++ b/lib/en57/repository.rb
@@ -58,7 +58,7 @@ module En57
         when "success"
           Success.new(position: row.first.fetch("position").then { Integer(it) })
         when "append_condition_violated"
-          Failure.new
+          Failure.new(position: row.first.fetch("position").then { Integer(it) })
         end
       rescue @adapter.serialization_error
         if attempts_remaining.positive?
diff --git a/test/pg_regress/expected/001_schema.out b/test/pg_regress/expected/001_schema.out
index 67c05f1..4976580 100644
--- a/test/pg_regress/expected/001_schema.out
+++ b/test/pg_regress/expected/001_schema.out
@@ -45,6 +45,7 @@ DECLARE
     req_tags text[];
     req_after bigint;
     appended_position bigint;
+    matched_position bigint;
 BEGIN
     FOREACH criterion IN ARRAY criteria LOOP
         req_after := (criterion ->> 'after')::bigint;
@@ -54,43 +55,43 @@ BEGIN
         req_tags := ARRAY ( SELECT DISTINCT
                 jsonb_array_elements_text(COALESCE(criterion -> 'tags', '[]'::jsonb)));
         IF cardinality(req_tags) > 0 THEN
-            IF EXISTS (
+            SELECT
+                max(e.position)
+            FROM (
                 SELECT
-                    1
-                FROM (
-                    SELECT
-                        t.event_id
-                    FROM
-                        en57.tags AS t
-                    WHERE
-                        t.value = ANY (req_tags)
-                    GROUP BY
-                        t.event_id
-                    HAVING
-                        count(*) = cardinality(req_tags)) AS matched
-                    JOIN en57.events AS e ON e.id = matched.event_id
-                WHERE (req_after IS NULL
-                    OR e.position > req_after)
+                    t.event_id
+                FROM
+                    en57.tags AS t
+                WHERE
+                    t.value = ANY (req_tags)
+                GROUP BY
+                    t.event_id
+                HAVING
+                    count(*) = cardinality(req_tags)) AS matched
+            JOIN en57.events AS e ON e.id = matched.event_id
+        WHERE (req_after IS NULL
+                OR e.position > req_after)
                 AND (criterion -> 'types' IS NULL
-                    OR e.type = ANY (req_types))) THEN
-        RETURN ROW ('append_condition_violated',
-            NULL)::en57.append_result;
-        END IF;
-    ELSE
-        IF EXISTS (
+                    OR e.type = ANY (req_types))
+            INTO
+                matched_position;
+        ELSE
             SELECT
-                1
+                max(e.position)
             FROM
                 en57.events AS e
             WHERE (req_after IS NULL
                 OR e.position > req_after)
-            AND (criterion -> 'types' IS NULL
-                OR e.type = ANY (req_types))) THEN
-    RETURN ROW ('append_condition_violated',
-        NULL)::en57.append_result;
-    END IF;
-END IF;
-END LOOP;
+                AND (criterion -> 'types' IS NULL
+                    OR e.type = ANY (req_types))
+            INTO
+                matched_position;
+        END IF;
+        IF matched_position IS NOT NULL THEN
+            RETURN ROW ('append_condition_violated',
+                matched_position)::en57.append_result;
+        END IF;
+    END LOOP;
     WITH inserted_events AS (
 INSERT INTO en57.events (id, type, data, meta)
         SELECT
diff --git a/test/test_integration.rb b/test/test_integration.rb
index 1f3a788..a33cdec 100644
--- a/test/test_integration.rb
+++ b/test/test_integration.rb
@@ -68,7 +68,7 @@ module En57
           )
 
           assert_equal(
-            Failure.new,
+            Failure.new(position: 1),
             event_store.append(
               [Event.new(id: ids[1], type: "ShipmentScheduled")],
               fail_if: event_store.read.of_type("OrderPlaced"),
@@ -110,7 +110,7 @@ module En57
           )
 
           assert_equal(
-            Failure.new,
+            Failure.new(position: 1),
             event_store.append(
               [Event.new(id: ids[1], type: "ShipmentScheduled")],
               fail_if: event_store.read.of_type("OrderPlaced").after(0),
diff --git a/test/test_repository.rb b/test/test_repository.rb
index 123dd1e..17cb8df 100644
--- a/test/test_repository.rb
+++ b/test/test_repository.rb
@@ -543,7 +543,7 @@ module En57
         connection.expect(:exec, nil, ["COMMIT"])
 
         assert_equal(
-          Failure.new,
+          Failure.new(position: 3),
           Repository.new(
             PgAdapter.for_connection(connection),
             JsonSerializer.new,
@@ -644,7 +644,8 @@ module En57
 
     def success_result = [{ "status" => "success", "position" => "1" }]
 
-    def failure_result = [{ "status" => "append_condition_violated" }]
+    def failure_result =
+      [{ "status" => "append_condition_violated", "position" => "3" }]
 
     def append_events = [Event.new(id: ids[0], type: "OrderPaid")]